NEW DELHI (AFP) India and the United States are likely to sign a 3.5-billion-dollar defence deal, the biggest ever between the two countries, a report said Wednesday. The agreement will see the Indian Air Force buy 10 C-17 Globemaster transport aircraft that are expected to replace the ageing fleet of Russian Ilyushin IL-76, The Economic Times newspaper said, without citing sources. The deal, which is in its final stages, is likely to be signed in November when US President Barack Obama visits India. In February, New Delhi announced a 32-billion-dollar defence budget, a four percent increase on 2009, when spending was hiked by a quarter as the country seeks to modernise its armed forces. A top air force official earlier stated that Indias air force is just a third the size of Chinas and far short of the aircraft required to meet the security challenges facing the country.